Normally, if a call argument is a rematerializable Variable, it is rematerialized into a GPR (via the "lea" instruction) and then written into the appropriate arg space.

This is appropriate for arguments passed on the stack, but for register arguments, it forces an unnecessary copy through another register.

This CL allows that intermediate register copy to be removed.

The resulting code looks cleaner, but it is unlikely to have much effect on performance - there really aren't register pressure issues because lots of scratch registers are available right before the call (which kills all scratch registers).

BUG= none
R=jpp@chromium.org

Review URL: https://codereview.chromium.org/2080443002 .

BUG=https://bugs.chromium.org/p/nativeclient/issues/detail?id=4374
R=kschimpf@google.com, stichnot@chromium.org

Review URL: https://codereview.chromium.org/2079723002 .

BUG=none
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/2067183002 .

Patch from Sagar Thakur <sagar.thakur@imgtec.com>.

BUG=https://bugs.chromium.org/p/nativeclient/issues/detail?id=4374
R=kschimpf@google.com

Review URL: https://codereview.chromium.org/2067403002 .

The x86 lowering of bitcast between integers and floats forced the transfer through a stack slot (the original implementer *cough* *cough* wasn't aware of the movd instruction).  This requires excess instructions, but also a store to memory followed immediately by a load from that location is very slow.

This fixes the problem by using the movd instruction instead.

BUG= none
R=jpp@chromium.org

Review URL: https://codereview.chromium.org/2077503002 .

BUG=https://bugs.chromium.org/p/nativeclient/issues/detail?id=4374
R=kschimpf@google.com

Review URL: https://codereview.chromium.org/2068593003 .

The Om1 recipe also includes register allocation (minimal mode).

BUG= none
R=kschimpf@google.com

Review URL: https://codereview.chromium.org/2069953004 .

Originally, a call instruction was lowered like this:

  // %result = call @foo(...)
  %t1:eax = call foo
  %result = %t1:eax

Because t1 is pre-colored, it is not available as a substitution if the following instruction uses %result as a source operand.

To improve this, we copy it through an intermediate temporary:

  // %result = call @foo(...)
  %t1:eax = call foo
  %t2 = %t1:eax
  %result = %t2

BUG= none
R=eholk@chromium.org

Review URL: https://codereview.chromium.org/2064073005 .

BUG=https://bugs.chromium.org/p/nativeclient/issues/detail?id=4374
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/2064613006 .

The original code legalized *all* i64 constants into a register move, creating unnecessary instructions and slightly higher register pressure in most cases.

Generally, immediates can be used in 64-bit instructions as long as the immediate can be represented as a sign-extended 32-bit value.

BUG= none
R=jpp@chromium.org

Review URL: https://codereview.chromium.org/2063053002 .

BUG=https://bugs.chromium.org/p/nativeclient/issues/detail?id=4374
R=kschimpf@google.com

Review URL: https://codereview.chromium.org/2054943002 .

R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/2060203002 .

Patch from Mohit Bhakkad <mohit.bhakkad@imgtec.com>.

BUG=none
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/2051713002 .

Patch from Sagar Thakur <sagar.thakur@imgtec.com>.

This patch provides calling convention class for MIPS with support of integer and floating point types

R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/2052793003 .

Patch from Mohit Bhakkad <mohit.bhakkad@imgtec.com>.

X86 only.  The register availability peephole optimization during lowering disallows available register substitution when the variable is pre-colored.  This is for good reasons (too complex to be discussed here).  However, that leaves some potential substitutions on the table.

Specifically, this happens a lot around register arguments to function calls, both at the call site and in the prolog.

The simplest solution seems to be to launder the pre-colored variable through a separate infinite-weight variable, as implemented in this CL through a combination of such copies and extra legalize() calls.

There are other situations where this technique can also work, which may be handled in a separate CL.

This CL also fixes a problem where the stack pointer adjustment in the prolog is subject to dead-code elimination if the function has no epilog.  This would only happen in asm-verbose mode, in the final liveness analysis pass prior to code emission.

BUG= none
R=eholk@chromium.org

Review URL: https://codereview.chromium.org/2052683003 .

R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/2050473005 .

Patch from Mohit Bhakkad <mohit.bhakkad@imgtec.com>.

Also added a command line flag for AddressSanitizer

BUG=None
R=kschimpf@google.com

Review URL: https://codereview.chromium.org/2042063002 .

Introducing instructions for floating point format conversion.
These instructions are needed for full implementation of lowerCast
and missing floating point arithmetic instruction frem.

BUG=
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/2024183002 .

Patch from Srdjan Obucina <Srdjan.Obucina@imgtec.com>.

BUG=none
R=jpp@chromium.org

Review URL: https://codereview.chromium.org/2022063003 .

Patch from Sagar Thakur <sagar.thakur@imgtec.com>.

The problem is that because of C++ integral promotion rules, many of the i8 and i16 arithmetic tests were actually being performed as i32 operations.  Thus we weren't actually testing everything we meant to test.

The fix is to have a python script auto-generate the relevant tests with proper typing.

BUG= none
R=eholk@chromium.org, jpp@chromium.org, kschimpf@google.com

Review URL: https://codereview.chromium.org/2013863002 .

BUG=None
R=kschimpf@google.com

Review URL: https://codereview.chromium.org/2028733002 .

- InstMIPS32Memory class is added to represent memory related instructions(load/store). I will add remaining load/store instructions if you are okay with this patch.

- Changed uncond_br.ll test as it was failing due to hardcoded label no. expected in output.

R=jpp@chromium.org, stichnot@chromium.org

Review URL: https://codereview.chromium.org/2005823002 .

Patch from Mohit Bhakkad <mohit.bhakkad@imgtec.com>.

R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/2017043002 .

Patch from Sagar Thakur <sagar.thakur@imgtec.com>.

This patch introduces floating point registers used for 32-bit
operations, and basic handling of FP values in operands. It is
partial work needed as a base for further work.

R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/1993993004 .

Patch from Srdjan Obucina <Srdjan.Obucina@imgtec.com>.

Adds Cfg::localCse for basic-block local common-subexpression elimination
If we have
    t1 = op b c
    t2 = op b c
This pass will replace future uses of t2 in a basic block by t1.

To enable, use -enable-experimental in O2

BUG=none
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/1997443002 .

Added implementation for conditional branch instructions.

R=jpp@chromium.org, stichnot@chromium.org

Review URL: https://codereview.chromium.org/1993773004 .

Patch from Sagar Thakur <sagar.thakur@imgtec.com>.

This patch adds support for missing integer division instruction sdiv, udiv, srem, urem.

R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/1989303002 .

Patch from Srdjan Obucina <Srdjan.Obucina@imgtec.com>.

This patch adds support for logical operations ashr, lshr and shl.

R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/1975283002 .

Patch from Srdjan Obucina <Srdjan.Obucina@imgtec.com>.

Clang doesn't realize that the end of method
NaClBitstreamCursor::readArrayAbbreviatedField is unreachable. Add
unreachable call to make the compiler happy.

BUG=None
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/1963193003 .

The README.txt file is new; all other files under pnacl-llvm/ are copied verbatim from the pnacl-llvm repo.

BUG= none
R=kschimpf@google.com

Review URL: https://codereview.chromium.org/1960393002 .

The purpose is to allow pnacl-sz to be built within an LLVM checkout (version 3.9 or later), and not require the complex PNaCl build environment.

Within an LLVM checkout, one would do something like the following:
  cd projects
  git clone https://chromium.googlesource.com/native_client/pnacl-subzero
  # change to LLVM build directory
  cmake -G "Ninja" <path_to_llvm_source_dir>
  ninja

A follow-on CL will add in the PNaCl bitcode reader source files that are needed for compiling and linking.

BUG= none
R=jpp@chromium.org

Review URL: https://codereview.chromium.org/1961743002 .

This patch adds support for sext, zext, trunc operations on i8, i16, i32 source operand types. Support for i1 source operand type will follow.

R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/1948093002 .

Patch from Sagar Thakur <sagar.thakur@imgtec.com>.

Introduces a new BooleanVariable type which represents zero-extended
variables generated from an i1, saving a pointer to the original
i1. The Wasm frontend uses this to avoid comparing against 0 if
possible when translating branches. This led to about a 12%
improvement on the bzip2 spec benchmark.

This change also adds the -wasm-disable-bounds-check command line
option which omits bounds checking code.

BUG= https://bugs.chromium.org/p/nativeclient/issues/detail?id=4369
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/1961583002 .

Also improve some diagnostic output in the Makefile.

BUG= none
R=jpp@chromium.org

Review URL: https://codereview.chromium.org/1941593002 .

Previously we were writing large numbers of zeros to the output
file. This change only writes out the initialized portion and
allocates the full address space at runtime. This reduces compile time
by around 50%.

This change also adds a couple of WASM-specific timers.

BUG= https://bugs.chromium.org/p/nativeclient/issues/detail?id=4369
R=jpp@chromium.org, stichnot@chromium.org

Review URL: https://codereview.chromium.org/1938643002 .

This change fills in several more runtime functions needed by several
benchmarks, as well as changing the buffer handling in the WASM
decoder. Now the decoder will resize the buffer as needed to
accomodate large .wasm modules.

Tracing can now be enabled on runtime functions to aid with
debugging. Additionally, runtime failures such as bounds check
failures or invalid indirect function calls tell what kind of failure
occured.

BUG= https://bugs.chromium.org/p/nativeclient/issues/detail?id=4369
R=jpp@chromium.org, stichnot@chromium.org

Review URL: https://codereview.chromium.org/1918213003 .

This CL enables subzero to lower shufflevector instructions in x86 using
pshufb (only for SSE 4.1)

BUG= https://bugs.chromium.org/p/nativeclient/issues/detail?id=4136
BUG= https://bugs.chromium.org/p/nativeclient/issues/detail?id=4077
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/1917863004 .

BUG= https://bugs.chromium.org/p/nativeclient/issues/detail?id=4136
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/1909013002 .

Cleans up and generally improves memory handling in
WASM. WasmTranslator now outputs the number of pages requested so the
runtime can do correct bounds checks. The runtime also initializes the
stack pointer correctly (stored at address 1024), so we no longer have
to deal with negative pointers. This allows bounds checks to be done
with a single comparison against the size of the heap. Because of
this, we now support non-power-of-two heap sizes.

Sbrk is implemented by having the runtime keep track of the current
heap break and incrementing it as necessary. The heap break is
initialized to the start of the first page beyond any initialized data
in the WASM heap.

These changes allow us to pass the complete set of torture tests that
are passing on the Wasm waterfall.

BUG= https://bugs.chromium.org/p/nativeclient/issues/detail?id=4369
R=kschimpf@google.com, stichnot@chromium.org

Review URL: https://codereview.chromium.org/1913153003 .

R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/1898743002 .

Patch from Sagar Thakur <sagar.thakur@imgtec.com>.